Communication System, Communication Method and Base Station

1. A communication system comprising a mobile station that transmits a data signal and a plurality of base stations receiving the data signal transmitted by the mobile station, the communication system including: as the base stations, at least, one first base station having a first signal detector detecting a first data signal that was generated by coding information bits transmitted from the mobile station; and, at least, one second base station having a second signal detector that detects a data signal received by the second base station, using a detection result which the first base station has detected, wherein the second signal detector detects a second data signal other than the data signal transmitted by the mobile station by removing the first data signal from data signals received by the second base station, the second signal detector detects a third data signal transmitted by the mobile station among the data signals received by the second base station, by using the detected second data signal, and the first data signal and the third data signal are signals generated by coding the identical information bits.

2. The communication system according to claim 1 , wherein the second base station further comprises a decoder that performs a decoding process on the detection result which the second signal detector has detected from the data signal, and the second signal detector, using a result of the decoding process, performs detection of the third data signal transmitted by the mobile station.

3. The communication system according to claim 1 , wherein the first base station further comprises a combiner that combines a result which the first signal detector has detected from the first data signal and a result which the second signal detector has detected from the third data signal.

4. The communication system according to claim 2 , wherein the second base station further comprises a combiner that combines a result which the first signal detector has detected from the first data signal and a result which the second signal detector has detected from the third data signal, and the decoder performs the decoding process on an output signal of the combiner.

5. The communication system according to claim 1 , wherein the mobile station transmits a transmission timing measurement signal for measuring a timing at which the mobile station will transmit the data signal, to the first base station and the second base station.

6. The communication system according to claim 1 , wherein the first base station includes: a control signal generator that generates offset information on a timing at which the mobile station transmits the data signal, based on a reference timing which the first base station holds; and a radio unit configured to transmit a control signal including the offset information with respect to the timing, and, the mobile station transmits the data signal in accordance with a resource allocation information based on the transmission timing offset information notified by the control signal.

7. The communication system according to claim 6 , wherein the second base station determines whether or not the timing at which the data signal transmitted by the mobile station using the resource allocation information falls beyond Guard Interval (GI) length.

8. The communication system according to claim 6 , wherein the second base station requests the first base station to transmit the detected result of the first data signal transmitted by the mobile station.

9. The communication system according to claim 1 , wherein the second base station includes: a control signal generator that generates offset information on a timing at which the mobile station transmits the data signal, based on a reference timing which the first base station holds; and a radio unit configured to transmit a control signal including the offset information with respect to the timing, and, the mobile station transmits the data signal in accordance with a resource allocation information based on the transmission timing offset information notified by the control signal.

10. The communication system according to claim 9 , wherein the second base station determines whether or not the timing at which the data signal transmitted by the mobile station using the resource allocation information falls beyond Guard Interval (GI) length.

11. The communication system according to claim 1 , wherein the first base station further comprises: a decoder that performs a decoding process on a result detected by the first signal detector; and an upper layer that transmits the result of the decoding process by the decoder, or the result of the decoding process on the first data signal transmitted by the mobile station, to the second base station.

12. The communication system according to claim 1 , wherein the second signal detector further includes: a replica generator that generates a received signal replica of the data signal of the mobile station which the second base station has received, from the detection result which the first base station has detected from the data signal transmitted by the mobile station; and, an interference canceller that subtracts the received signal replica from the data signal.

13. The communication system according to claim 2 , wherein the second signal detector further includes: a replica generator that generates a received signal replica of the data signal of communication apparatus other than the mobile station, received by the second base station, from the result of the decoding process of the decoder; and, an interference canceller that subtracts the received signal replicas from the data signal.

14. A communication method for use in a communication system comprising a mobile station that transmits a data signal and at least first and second base stations receiving the data signal transmitted by the mobile station, the communication method comprising the steps of: a first step of detecting, by the first base station, a first data signal that was generated by coding information bits transmitted from the mobile station; a second step of detecting, by the second base station, a second data signal other than the data signal transmitted by the mobile station by removing the first data signal from data signals received by the second base station, by using a result detected in the first step; and a third step of detecting a third data signal transmitted by the mobile station among the data signals received by the second base station, by using a detected result of the second data signal, wherein the first data signal and the third data signal are signals generated by coding the identical information bits.

15. A second base station connected to a communication system comprising a mobile station that transmits a data signal and a first base station configured to detect the data signal transmitted by the mobile station, the second base station comprising: a second signal detector that detects the data signal received by the second base station, using a result which the first base station has detected a first data signal that was generated by coding information bits transmitted from the mobile station, wherein the second signal detector detects a second data signal other than the data signal transmitted by the mobile station by removing the first data signal from data signals received by the second base station, the second signal detector detects a third data signal transmitted by the mobile station among the data signals received by the second base station, by using the detected result of the second data signal, and the first data signal and the third data signal are signals generated by coding the identical information bits.

16. The second base station according to claim 15 , further comprising: a decoder configured to perform a decoding process on the detection result which the second signal detector has detected from the data signal, wherein the second signal detector, using a result of the decoding process, performs detection of the third data signal transmitted by the mobile station.

17. The second base station according to claim 16 , further comprising: a combiner configured to combine a result which the first signal detector has detected from the first data signal and a result which the second signal detector has detected from the third data signal, wherein the decoder performs the decoding process on an output signal of the combiner.

18. The second base station according to claim 15 , further comprising: a replica generator configured to generate a received signal replica of the data signal of the mobile station which the second station has received, from the detection result which the first base station has detected the first data signal; and, an interference canceller configured to subtract the received signal replica from the data signal received by the second base station.

19. The second base station according to claim 16 , further comprising: a replica generator configured to generate a received signal replica of the second data signal from the result of the decoding process of the decoder; and an interference canceller configured to subtract the received signal replicas from the data signal received by the second base station.